The present invention relates to an apparatus and method for treating used cooking liquid resulting from the cooking of food products and, in particular, to such a treatment using increased hydrostatic pressure on the used cooking liquid to minimize the amount of effluent and the use of xe2x80x9cmakeupxe2x80x9d liquid.
Cooking of foods in a heated liquid typically requires the liquid within which the food is being cooked to combine with the food as well as provide a cooking temperature sufficient for completing the cooking process. By way of example, when cooking food products such as pasta, rice, legumes, or vegetables, large amounts of water are absorbed during the cooking process, with the weight of the cooked food generally increasing to 250% of the original dry weight for pasta, for instance.
Not all the cooking water is absorbed, however, and the nonabsorbed water typically contains a residue from the food, such as starch from pasta or legumes, that interferes with the cooking of additional food and is also detrimental to product quality. During the production process, this wastewater ultimately must be drained off, with additional xe2x80x9cmakeupxe2x80x9d water added to the cooking vessel as needed to maintain a desired volume.
The disposal of the wastewater is becoming of increasing concern for food manufacturers, as is the use of fresh water in the production process. The concern arises both from economic considerations, since disposal typically entails the payment of a surcharge, and the xe2x80x9cmakeupxe2x80x9d water incurs additional costs, and from ecological considerations of treating of the wastewater and using excess water.
It is an object of the present invention to provide an apparatus and method for treating used cooking liquid from a cooking process.
It is also an object to provide such an apparatus and method for reducing a requirement for cooking fluid.
It is an additional object to provide such an apparatus and method for pretreating food to minimize the production of wastewater and usage of xe2x80x9cmakeupxe2x80x9d water.
It is a further object is to provide such an apparatus and method that assist in reducing potential microbial contamination.
It is another object to provide such an apparatus and method for improving a quality of the cooked foodstuff.
These and other objects are achieved by the present invention, one aspect of which comprises a method for treating used cooking liquid from a cooking process. The method comprises the steps of removing a portion of used liquid cooking medium from a cooking vessel and channeling the portion of cooking medium to a treatment vessel. The cooking medium in the treatment vessel is then subjected to a pressure substantially greater than ambient atmospheric pressure, and it is heated in the treatment vessel to a temperature greater than an atmospheric pressure boiling point for a sufficient time to restore the cooking medium to a condition suitable for cooking. Finally the treated cooking medium is returned to the cooking vessel from the treatment vessel.
It will be understood by one of skill in the art that the treatment vessel may in fact be integral to the cooking vessel, but sealable for attaining increased pressure and temperature, and thus that the xe2x80x9cchannelingxe2x80x9d may comprise flowing liquid from the cooking vessel into a treatment sector for pressurization and heating.
The system of the present invention comprises a treatment vessel sealable against a pressure that is substantially greater than atmospheric pressure. Means are provided for automatically channeling a portion of used liquid cooking medium between a cooking vessel and the treatment vessel. Means are also provided for heating the cooking medium in the treatment vessel when sealed to a temperature greater than an atmospheric pressure boiling point. The heating should persist for a sufficient time to restore the cooking medium to a condition suitable for cooking, and should cause a rise in pressure to a treatment level substantially greater than atmospheric pressure.